Osteoarthritis (OA) is the most common type of arthritis and a leading cause of disability. It is a non-inflammatory, degenerative joint disease characterized by progressive loss of articular cartilage, subchondral bone sclerosis, osteophyte formation, changes in the synovial membrane, and an increased volume of synovial fluid with reduced viscosity and hence changed lubrication properties.
Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease of unknown cause. Genetic, environmental, hormonal, immunologic, and infectious factors can play significant roles. The hallmark feature of this condition is persistent symmetric polyarthritis that affects the hands and feet, although any joint lined by a synovial membrane can be involved. This is due to the accumulation of and proliferation of inflammatory cells in the synovial lining, known as synovitis. Extra-articular involvement of organs such as the skin, heart, lungs, and eyes can be significant.
Intraarticular (IA) drug injection is an attractive treatment approach for treatment of arthritis, including OA and RA. The various steroid and hyaluronic acid formulations on the market are considered effective, but require frequent IA injections and provide only short-term symptomatic relief. Other crystal suspension formulations, which require large bore needles for IA injection are not suitable for treating small joints and can produce a crystal-induced synovitis. The available systemic treatments also have shortcomings, most notably side effects.
In view of the deficiencies outlined above, there is a need for methods for treating arthritis with less frequent IA injection and/or longer-term pain relief. The methods disclosed herein address this need as well as other important needs.